JERSEY CITY, NJ – A rookie police officer responding to an armed robbery call at a 24-hour drugstore was fatally shot early Sunday by a suspect who had snatched a gun from an armed security guard inside, officials said.

Jersey City Officer Melvin Santiago, 23, was shot in the head while still in his police vehicle as he and his partner responded to a call at a Walgreens at about 4.a.m., Mayor Steven Fulop said. He was pronounced dead at a hospital.